Body mass index, height, and osteoporotic fracture risk in community-dwelling Japanese people aged 40-74 years.

INTRODUCTION: The association between body size and fracture risk is complex and varies by sex and ethnicity. This study aimed to examine associations of body mass index (BMI) and height with osteoporotic fracture risk in middle-aged and older people. MATERIALS AND METHODS: This 10-year cohort study included 13,151 community-dwelling Japanese people aged 40-74 years. A self-administered questionnaire survey was conducted at baseline to obtain information on demographic characteristics, body size, lifestyle, and disease history. BMI (kg/m2) was categorized as underweight (< 18.5), low-normal (18.5-21.7), high-normal (21.8-24.9), overweight (25.0-29.9), and obese (≥ 30.0). Height was categorized into quartiles. All incident cases of major osteoporotic fractures, including fractures of the distal radius, neck of the humerus, neck or trochanter of the femur, and vertebrae, were obtained from medical records during follow-up. RESULTS: Mean participant age was 58.8 years. In men, the underweight group had a significantly higher hazard ratio (HR) for total fracture (adjusted HR = 2.46), and the obese group had significantly higher HRs for total (adjusted HR = 3.01) and vertebral (HR = 3.77) fractures relative to the reference (overweight) group. No significant associations were observed between BMI and risk of any fracture in women. Higher quartiles of height were associated with higher vertebral fracture risk (adjusted P for trend = 0.023) only in women. CONCLUSION: BMI and osteoporotic fracture risk showed a U-shaped association in men, whereas higher height was associated with higher vertebral fracture risk in women, suggesting sex-dependent differences in these associations.

Validity of the intake of sugars, amino acids, and fatty acids estimated using a self-administered food frequency questionnaire in middle-aged and elderly Japanese: the Japan Public Health Center-based Prospective Study for the Next Generation (JPHC-NEXT) Protocol Area.

BACKGROUND: The Japanese database of food composition was revised in 2020, during which both the number of food items and the number of food items measured for sugars, amino acids, and fatty acids were increased. We evaluated the validity of estimated intakes of sugars, amino acids and fatty acids using a long-food frequency questionnaire (FFQ) among middle-aged and elderly Japanese. METHODS: From 2012 to 2013, 240 men and women aged 40-74 years from five areas in the JPHC-NEXT protocol were asked to respond to the long-FFQ and provide a 12-day weighed food record (WFR) as reference. The long-FFQ, which included 172 food and beverage items and 11 seasonings, was compared with a 3-day WFR, completed during each distinct season, and validity was assessed using Spearman's correlation coefficients. RESULTS: Percentage differences based on the long-FFQ with the 12-day WFR in men and women varied from -83.9% to 419.6%, and from -75.8% to 623.1% for sugars, -17.5% to 2.8% and -5.8% to 19.6% for amino acids, and -58.5% to 78.8% and -43.4% to 129.3% for fatty acids, respectively. Median values of correlation coefficients for the long-FFQ in men and women were 0.52 and 0.42 for sugars, 0.38 and 0.37 for amino acids, and 0.42 and 0.42 for fatty acids, respectively. CONCLUSIONS: The long-FFQ provided reasonable validity in estimating the intakes of sugars, amino acids, and fatty acids in middle-aged and elderly Japanese. Although caution is warranted for some nutrients, these results may be used in future epidemiological studies.

Chronic Pain in the Lower Extremities and Low Back is Associated With Recurrent Falls in Community-Dwelling Japanese People Aged 40-74 Years.

OBJECTIVE: To determine the longitudinal association between chronic pain in the lower extremities and low back and the odds of recurrent falls in middle-aged and older people. DESIGN: A cohort study. SETTING: Communities in Japan. PARTICIPANTS: Participants were 7540 community-dwelling volunteers aged 40-74 years (N=7540). The baseline survey was a self-administered questionnaire conducted between 2011-2013. Predictors were presence of chronic pain in the knee, foot or ankle, and low back, with the degree of pain categorized as none, very mild/mild, moderate, or severe/very severe. Covariates in the multivariate model of chronic pain in a site were demographics, body mass index, physical activity level, disease history, and chronic pain in the other 2 sites. Logistic regression analysis was used to calculate odds ratios (ORs). INTERVENTIONS: None. MAIN OUTCOME MEASURE(S): Recurrent falls in the year before the 5-year follow-up survey. RESULTS: Mean participant age was 60.2 years. Higher degrees of chronic pain were associated with higher odds of recurrent falls for the knee (P=.0002) with a higher OR of 1.48 (95% CI: 1.11-1.97), for the foot or ankle (P=.0001) with a higher OR of 1.97 (95% CI: 1.36-2.86), and for the low back (P=.0470) with a higher OR of 1.45 (95% CI: 1.09-1.91) in those with any degree of pain relative to those without pain. Higher degrees of chronic knee pain were associated with higher odds of recurrent falls in women (P=.0005), but not in men (P=.0813). Meanwhile, higher degrees of chronic low back pain were associated with the odds of recurrent falls in men (P=.0065), but not in women (P=.8735). CONCLUSIONS: Chronic pain in the knee, foot or ankle, and lower back was independently and dose-dependently associated with a higher risk of recurrent falls. A marked sex-dependent difference was also noted in the association.

Dietary sodium sources according to four 3-d weighed food records and their association with multiple 24-h urinary excretions among middle-aged and elderly Japanese participants in rural areas.

Reducing Na intake is an urgent global challenge, especially in East Asia and high-income Asia-Pacific regions. However, the sources of Na and their effects on urinary Na excretion have not been fully studied. We sought to clarify these sources and their association with urinary Na excretion. We examined four 3-d weighed food records and five 24-h urinary collections from each of 253 participants in Japan, aged 35-80 years, between 2012 and 2013. We compared the levels of Na according to four categories: foods contributing to discretionary or non-discretionary Na intake, the situation in which dishes were cooked and consumed, food groups and types of cuisine. We also conducted regression analysis in which 24-h urinary Na excretion was a dependent variable and the amounts of food intake in the four categories were independent variables. Levels of Na were the highest in discretionary intake (60·6 %) and in home-prepared dishes (84·0 %). Of the food groups, miso soup showed the highest percentage contribution to Na intake (13·3 %) after seasonings such as soya sauce. In the regression analysis, the standardised coefficient for foods of non-discretionary Na sources was larger than that for discretionary sources, whereas that for home-prepared dishes was consistent with the levels of Na in those foods. Pickled products, followed by fresh fish and shellfish, miso soup and rice, were associated with high urinary Na excretion. Thus, discretionary foods (such as miso soup) contribute the most to Na consumption, although non-discretionary intake (such as pickled vegetables) may influence urinary Na excretion.

Applicability of a Web-based 24-hour Dietary Recall Tool for Japanese Populations in Large-scale Epidemiological Studies.

BACKGROUND: Recent innovations in information and communication technology have made it possible to assess diet using web-based methods; however, their applicability in the general population remains unclear. Hence, we aimed to examine the applicability of a web-based 24-hour dietary recall (24HR) tool to large-scale epidemiological studies by determining the sampling rate and characteristics of randomly selected participants from a Japanese cohort study. METHODS: In total, 5,013 individuals were recruited from a cohort of 21,537 individuals, and 975 agreed to participate in this study. The participants selected either self-administered web-based dietary 24HR (self-administered 24HR) or interviewer-administered telephone-based 24HR (interviewer-administered 24HR) as the method for the dietary assessment and answered questions regarding the acceptability of the system. RESULTS: The response rate of the 975 participants was 19.4%, corresponding to approximately 4.5% of the total study sample. About half of them chose the self-administered 24HR (46.9%). The median time required for the self-administered and interviewer-administered 24HR was 25 and 27 minutes, respectively. In the self-administered 24HR, older people, regardless of sex, tended to require a longer time, and approximately 60% of the participants rated the ease of use of the system as "somewhat difficult" or "difficult." CONCLUSION: Characteristics of the participants in this study were not systemically different from those of the entire study sample. Improvements in the approach to entering cooking details and the dish name selection may be necessary for better acceptability in order to be accepted as a self-administered dietary recall tool.

Inverse Association between Fruit and Vegetable Intake and All-Cause Mortality: Japan Public Health Center-Based Prospective Study.

BACKGROUND: A dose-response and nonlinear association between fruit and vegetable intake and mortality has been reported in Europe and the United States, but little is known about this association in Asia. OBJECTIVES: This study aimed to evaluate the association of fruit and vegetable intake with all-cause, cancer, cardiovascular, and respiratory disease mortality in a Japanese cohort. METHODS: In the Japan Public Health Center-based prospective study, we included 94,658 participants (mean age: 56.4; 46.0% male) without cancer and cardiovascular disease at baseline. Information on fruit and vegetable intake was collected using a validated FFQ. The Cox proportional hazard model was used to estimate HRs and 95% CIs of each quintile of fruit and vegetable intake, separately, in relation to all-cause and cause-specific mortality using the first quintile as a reference. Nonlinear associations were evaluated using a likelihood ratio test, comparing a linear model with a restricted cubic spline model. RESULTS: During a median of 20.9 follow-up years (IQR: 19.6-23.8 y), 23,687 all-cause deaths were documented. After adjusting for age, sex, and potential confounding factors, fruit and vegetable intake was nonlinearly and significantly associated with lower all-cause mortality, with the fourth and fifth quintiles having comparable HRs (fruit: fourth quintile HR: 0.91; 95% CI: 0.87, 0.95 and fifth quintile HR: 0.92; 95% CI: 0.88, 0.96; P-nonlinearity < 0.001; vegetable: fourth quintile HR: 0.92; 95% CI: 0.88, 0.97 and fifth quintile HR: 0.93; 95% CI: 0.89, 0.98; P-nonlinearity = 0.002). Fruit intake was significantly associated with lower cardiovascular mortality (HR in the fifth quintile: 0.91; 95% CI: 0.83, 0.99; P-nonlinearity = 0.01). CONCLUSIONS: In the Japanese population, higher intake of fruits and vegetables was nonlinearly associated with decreased all-cause mortality. These findings may contribute to the establishment of dietary recommendations for enhancing life expectancy in Asia.

Non-alcoholic beverages intake and risk of CVD among Japanese men and women: the Japan Public Health Center study.

The association between the intake of non-alcoholic beverages and CVD in Asians is uncertain. The intake of non-alcoholic beverages was estimated in 77 407 participants of the Japan Public Health Centre-based cohort study aged 45-74 years. The Cox regression calculated the hazard ratios (HR) and 95 % CI for incident CVD according to sex-specific quintiles of intake of non-alcoholic beverages. A total of 4578 incident CVD (3751 strokes and 827 CHD) were diagnosed during a 13·6-year median follow-up. The risks of stroke and total CVD were lower for the highest v. lowest intake quintiles of non-alcoholic beverages in men and women: the multivariable HRs (95 % CIs) were 0·82 (0·71, 0·93, Ptrend = 0·005) and 0·86 (0·76, 0·97, Ptrend = 0·02), respectively, in men and were 0·73 (0·63, 0·86, Ptrend = 0·003) and 0·75 (0·65, 0·87, Ptrend = 0·005), respectively, in women. The reduced risk was evident for both ischaemic and haemorrhagic strokes and was mainly attributable to green tea consumption. The intake of non-alcoholic beverages from coffee and other beverages was not associated with the risk of CVD in both men and women. Also, there was no association between the intake of non-alcoholic beverages and the risk of CHD in either sex. In conclusion, the risks of stroke and total CVD were lower with a higher intake of non-alcoholic beverages in Japanese men and women.

Associations of Urinary and Dietary Sodium-To-Potassium Ratios with Albuminuria in Community-Dwelling Japanese Adults: A Cross-Sectional Study.

INTRODUCTION: The urinary sodium-to-potassium ratio is an indicator of dietary sodium intake and has been associated with reduced kidney function. However, less is known about its association with albuminuria, the other key component of chronic kidney disease, in the community-dwelling adult population. We examined the association of the spot urinary sodium-to-potassium ratio with albuminuria and compared spot urinary and dietary sodium-to-potassium ratios. METHODS: We quantified the association of the urinary sodium-to-potassium ratio with albuminuria in 6,274 Japanese adults (aged 40-97 years; 50.9% women) based on spot urine samples. We performed linear and logistic regression modeling to account for potential confounders. Elevated albuminuria was defined as a spot urinary albumin-to-creatinine ratio (ACR) ≥30 mg/g. We secondarily evaluated the dietary sodium-to-potassium ratio based on a food-frequency questionnaire. RESULTS: The median spot urinary and dietary sodium-to-potassium ratios were 2.70 (interquartile interval, 1.87-3.83) and 1.50 (1.21-1.84), respectively. The median ACR was 11.0 (6.0-24.0) mg/g. In a multivariable linear regression model, the spot urinary sodium-to-potassium ratio (per increment) was significantly associated with the natural logarithm of the ACR (regression coefficient, 0.023 [95% confidence interval {95% CI}, 0.007-0.038]). This result was consistent in a multivariable logistic regression model (adjusted odds ratio, 1.08 [95% CI: 1.04-1.12]). The corresponding estimates for the dietary sodium-to-potassium ratio were 0.139 (95% CI: 0.087-0.191) and 1.28 (95% CI: 1.14-1.45), respectively. CONCLUSIONS: Both spot urinary and dietary sodium-to-potassium ratios were associated with elevated albuminuria in community-dwelling Japanese adults. Our findings further support the potential usefulness of the spot urinary sodium-to-potassium ratio as an indicator of sodium intake and suggest a link between sodium intake and kidney damage.

Association of sugary drink consumption with all-cause and cause-specific mortality: the Japan Public Health Center-based Prospective Study.

BACKGROUND: Few epidemiologic studies have assessed the associations of sugary drink consumption with mortality outcomes among Asian populations. METHODS: This study included 70,486 participants in the Japan Public Health Center-based Prospective Study at the age of 45-74 years in 1995-1999. A validated food frequency questionnaire was used to assess the consumption of sugary drinks. We estimated the risk of total and cause-specific mortality associated with sugary drink consumption using Cox proportional hazards regression model. RESULTS: Mean follow-up was 17.1 years, during which 11,811 deaths were documented. Sugary drink consumption was associated with higher total mortality, with multivariate HR of 1.06 (95% CI 1.00-1.13) for quintile 3, 1.07 (95% CI 1.01-1.13) for quintile 4, and 1.15 (95% CI 1.09-1.22) for quintile 5, compared with quintile 1 (P < 0.001 for trend). Additionally, positive associations with cause-specific mortality were observed, including death from circulatory system diseases (quintile 5 vs quintile 1; HR, 1.23; 95% CI 1.09-1.38) and heart disease (quintile 5 vs quintile 1; HR, 1.35; 95% CI 1.14-1.60). CONCLUSION: In this large Japanese prospective study, sugary drink consumption was associated with all-cause and cause-specific mortality.

Dietary calcium and vitamin K are associated with osteoporotic fracture risk in middle-aged and elderly Japanese women, but not men: the Murakami Cohort Study.

Although dietary Ca, vitamin D and vitamin K are nutritional factors associated with osteoporosis, little is known about their effects on incident osteoporotic fractures in East Asian populations. This study aimed to determine whether intakes of these nutrients predict incident osteoporotic fractures. We adopted a cohort study design with a 5-year follow-up. Subjects were 12 794 community-dwelling individuals (6301 men and 6493 women) aged 40-74 years. Dietary intakes of Ca, vitamin D and vitamin K were assessed with a validated FFQ. Covariates were demographic and lifestyle factors. All incident cases of major osteoporotic limb fractures, including those of the distal forearm, neck of humerus, neck or trochanter of femur and lumbar or thoracic spine were collected. Hazard ratios (HR) for energy-adjusted Ca, vitamin D and vitamin K were calculated with the residual method. Mean age was 58·8 (sd 9·3) years. Lower energy-adjusted intakes of Ca and vitamin K in women were associated with higher adjusted HR of total fractures (Pfor trend = 0·005 and 0·08, respectively). When vertebral fracture was the outcome, Pfor trend values for Ca and vitamin K were 0·03 and 0·006, respectively, and HR of the lowest and highest (reference) intake groups were 2·03 (95 % CI 1·08, 3·82) and 2·26 (95 % CI 1·19, 4·26), respectively. In men, there were null associations between incident fractures and each of the three nutrient intakes. Lower intakes of dietary Ca and vitamin K were independent lifestyle-related risk factors for osteoporotic fracture in women but not men. These associations were robust for vertebral fractures, but not for limb fractures.

Associations between changes in fruit and vegetable consumption and weight change in Japanese adults.

BACKGROUND: Fruits and vegetables may induce greater satiety, reduce hunger, decrease energy intake, and modulate energy metabolism, thereby playing a role in weight loss. OBJECTIVE: To determine the associations between changes in fruit and vegetable consumption and weight change over a 5-year interval in Japanese adults. METHODS: This cohort study included 54,015 subjects (54.6% female, mean age 56.5 years) of the Japan Public Health Center-based Prospective Cohort Study who had no known history of major chronic diseases at baseline. Data on fruit and vegetable consumption were collected using a validated food frequency questionnaire. Body weight was self-reported. We used multivariable linear mixed-effects regression models to examine the associations between changes in fruit and vegetable consumption and change in body weight. RESULTS: On average, body weight decreased by 25 g [95% confidence interval (CI), 3, 47] for every 100 g/d increase in total vegetable consumption. Change in fruit consumption was nonlinearly associated with weight change. Fruit consumption was directly associated with weight change among subjects who increased consumption (70 g; 95% CI, 39, 101) but was not associated with weight change among subjects who reduced or did not change fruit consumption. These associations did not vary by sex, age, and body mass index (BMI) at baseline. The association with vegetables was restricted to yellow/red vegetables (- 74 g; 95% CI, - 129, - 18) and allium vegetables (- 129 g; 95% CI, - 231, - 28). Lower-fiber vegetables were inversely associated with weight change, whereas lower-fiber fruits or higher-energy fruits were directly associated with weight change beyond 0 g/d change in consumption. CONCLUSIONS: Change in vegetable consumption was inversely associated with weight change while fruit consumption was positively associated with weight change among subjects who increased consumption. The influence of fruits and vegetables on weight change may depend on the characteristics of the fruits and vegetables.

Dietary glycemic index, glycemic load and mortality: Japan Public Health Center-based prospective study.

PURPOSE: Long-term associations of dietary glycemic index (GI) and glycemic load (GL) with mortality outcomes remain unclear. METHODS: The present analysis included 72,783 participants of the Japan Public Health Center-based Prospective Study. Participants who responded to the 5-year follow-up questionnaire in 1995-1999 were followed-up until December 2015. We estimated the risk of total and cause-specific mortality associated with GI and GL using Cox proportional hazards regression models. RESULTS: During 1,244,553 person years of follow-up, 7535 men and 4913 women died. GI was positively associated with all-cause mortality. As compared with the lowest quartile, the multivariable HR for those who had the highest quartile of GI was 1.14 (95% CI 1.08-1.20). The HRs for death comparing the highest with the lowest quartile were 1.28 (95% CI 1.14-1.42) for circulatory system diseases, 1.33 (95% CI 1.14-1.55) for heart disease, 1.32 (95% CI 1.11-1.57) for cerebrovascular disease, and 1.45 (95% CI 1.18-1.78) for respiratory diseases. GI was not associated with mortality risks of cancer and digestive diseases. GL showed a null association with all-cause mortality (highest vs lowest quartile; HR 1.04; 95% CI 0.96-1.12). However, among those who had the highest quartile of GL, the HRs for death from circulatory system diseases was 1.24 (95% CI 1.05-1.46), cerebrovascular disease was 1.34 (95% CI 1.03-1.74), and respiratory diseases was 1.35 (95% CI 1.00-1.82), as compared with the lowest quartile. CONCLUSION: In this large prospective cohort study, dietary GI and GL were associated with mortality risks.

Comparison between the impact of fermented and unfermented soy intake on the risk of liver cancer: the JPHC Study.

PURPOSE: The aim of this study was to compare the impact of fermented and unfermented soy intake, based on the following soy-derived products: tofu, soymilk, natto, and miso, on the risk of liver cancer among Japanese adults. METHODS: 75,089 Participants of the Japan Public Health Center-based Prospective Study (JPHC Study) were followed from the time of the 5-year follow-up questionnaire until the end of 2012-2013. Subjects with available data on hepatitis B virus (HBV) and hepatitis C virus (HCV) infection status from blood samples (n = 14,016) and those who were anti-HCV antibody (anti-HCV) or hepatitis B virus antigen (HBsAg) positive (n = 1033) were also analyzed separately. Cox proportional hazard models were employed to calculate hazard ratios (HRs) and 95% confidence intervals (95% CIs). RESULTS: During 1,145,453 person-years, 534 newly diagnosed cases of liver cancer were identified in the JPHC Study. For miso intake among men, the multivariate-adjusted highest versus lowest quartile HR was 0.65 (95% CI, 0.48-0.89); p for trend = 0.006. Results were similar in those who were anti-HCV or HBsAg positive, 0.24 (0.08-0.70); p for trend = 0.004 highest versus lowest tertile. For the sub-analysis among only participants with known hepatitis infection status and HCV and HBsAg adjustment, a similar association was observed. In the multivariate complete cohort analysis, among women, the highest intake of fried tofu was inversely associated with the risk of liver cancer, HR = 0.45 (0.26-0.80); p for trend = 0.014. CONCLUSIONS: We observed no association between total soy intake, fermented and unfermented, and risk of liver cancer, and only an inverse association between miso intake and liver cancer among men.

Education, household income, and depressive symptoms in middle-aged and older Japanese adults.

BACKGROUND: Income inequality has dramatically increased worldwide, and there is a need to re-evaluate the association between socio-economic status (SES) and depression. Relative contributions of household income and education to depression, as well as their interactions, have not been fully evaluated. This study aimed to examine the association between SES and depressive symptoms in Japanese adults, focusing on interactions between education and household income levels. METHODS: This cross-sectional study used data from baseline surveys of two cohort studies. Participants were 38,499 community-dwelling people aged 40-74 years who participated in baseline surveys of the Murakami cohort study (2011-2012) and Uonuma cohort study (2012-2015) conducted in Niigata Prefecture, Japan. Information regarding marital status, education level, household income, occupation, activities of daily living (ADL), and history of cancer, myocardial infarction, stroke, and diabetes was obtained using a self-administered questionnaire. Depressive symptoms were examined using the Center for Epidemiologic Studies Depression Scale (CES-D). Logistic regression analysis was used to obtain odds ratios (ORs). Covariates included age, sex, marital status, education, household income, occupation, ADL, and disease history. RESULTS: Individuals with higher education levels had lower ORs (adjusted P for trend = 0.0007) for depressive symptoms, independently of household income level. The OR of the university-or-higher group was significantly lower than that of the junior high school group (adjusted OR = 0.79). Individuals with lower household income levels had higher ORs (adjusted P for trend< 0.0001) for depressive symptoms, independently of education level. The type of occupation was not associated with depressive symptoms. In subgroup analyses according to household income level, individuals with higher education levels had significantly lower ORs in the lowest- and lower-income groups (adjusted P for trend = 0.0275 and 0.0123, respectively), but not in higher- and highest-income groups (0.5214 and 0.0915, respectively). CONCLUSIONS: Both education and household income levels are independently associated with the prevalence of depressive symptoms, with household income levels showing a more robust association with depressive symptoms than education levels. This suggests that a high household income level may offset the risk of depressive symptoms from having a low education level.

Predictors of decline in vitamin D status in middle-aged and elderly individuals: a 5-year follow-up study.

Little is known about predictors of decline in vitamin D status (vitamin D decline) over time. We aimed to determine demographic and lifestyle variables associated with vitamin D decline by sufficiently controlling for seasonal effects of vitamin D uptake in a middle-aged to elderly population. Using a longitudinal study design within the larger framework of the Murakami Cohort Study, we examined 1044 individuals aged between 40 and 74 years, who provided blood samples at baseline and at 5-year follow-up, the latter of which were taken on a date near the baseline examination (±14 d). Blood 25-hydroxyvitamin D (25(OH)D) concentrations were determined with the Liaison® 25OH Vitamin D Total Assay. A self-administered questionnaire collected demographic, body size and lifestyle information. Vitamin D decline was defined as the lowest tertile of 5-year changes in blood 25(OH)D (Δ25(OH)D) concentration (<6·7 nmol/l). Proportions of those with vitamin D decline were 182/438 (41·6 %) in men and 166/606 (27·4 %) in women (P < 0·0001). In men, risk of vitamin D decline was significantly lower in those with an outdoor occupation (P = 0·0099) and those with the highest quartile of metabolic equivalent score (OR 0·34; 95 % CI 0·14, 0·83), and higher in those with 'university or higher' levels of education (OR 2·92; 95 % CI 1·04, 8·19). In women, risk of vitamin D decline tended to be lower with higher levels of vitamin D intake (Pfor trend = 0·0651) and green tea consumption (Pfor trend = 0·0025). Predictors of vitamin D decline differ by sex, suggesting that a sex-dependent intervention may help to maintain long-term vitamin D levels.

Study Design and Baseline Profiles of Participants in the Uonuma CKD Cohort Study in Niigata, Japan.

BACKGROUND: Evidence for primary prevention of chronic kidney disease (CKD) is insufficient. The population-based prospective Uonuma CKD cohort study aims to explore associations of lifestyle and other risk factors with CKD. We report here the study design and baseline profiles. METHODS: All 67,322 residents aged ≥40 years in Minamiuonuma City, Uonuma City, and Yuzawa Town, Niigata Prefecture, Japan and 11,406 participants who attended local health-check examinations were targeted for baseline questionnaire and biochemical sampling, respectively. Information was gathered from 43,217 (64.2%) questionnaires and 8,052 (70.6%) biochemical samples; 6,945 participants consented to both questionnaire and biochemical sampling at baseline, conducted between fiscal years 2012 and 2015. Participants provided information regarding sociodemographic, lifestyle, and self-reported outcomes. Urine albumin-to-creatinine ratio (ACR) and estimated glomerular filtration rate (eGFR) were measured. The primary outcome is CKD based on self-report and biochemical/clinical diagnosis. RESULTS: Mean age of questionnaire respondents was 63.3 (standard deviation [SD], 12.5) years for men and 64.3 (SD, 13.3) years for women. Among participants who submitted urine samples, median ACR was 10.0 (interquartile range [IQR], 5.0-24.0) mg/g for men and 13.0 (IQR, 7.7-27.0) mg/g for women, and median eGFR was 73.6 mL/min/1.73 m2 (IQR, 63.5-84.5) for men and 73.5 mL/min/1.73 m2 (IQR, 64.4-83.5) for women. ACR 30 mg/g or more was found in 1,741 participants (21.7%) and eGFR <60 mL/min/1.73 m2 in 1,361 participants (16.9%). CONCLUSION: The Uonuma CKD cohort study was established to investigate the impact of lifestyle on CKD development and to provide data for preventing the onset and progression of CKD.

Development and validation of nutrient estimates based on a food-photographic record in Japan.

BACKGROUND: Previous studies have reported that estimates of portion size, energy, and macronutrients such as carbohydrates, proteins, and fat based on the food-photographic record closely correlate with directly weighed values. However, the correlation based on a large sample of the test meal with the evidence of many nutrients is yet to be determined. We conducted this study to assess the correlation and difference between the food-photographic record and weighed results for 44 nutrients based on a larger number of test meals than those in previous studies. METHODS: We assessed the nutrients of test meals using a food-photographic record and direct weighing and compared the results of the two methods. Twenty participants prepared a total of 1163 test meals. Each participant cooked 28-29 different kinds of dishes. Five participants cooked the same dish with their own recipes. For the most commonly consumed 41 dishes, 20 participants served a meal with their usual portion size. For the remaining 73 dishes, five participants served a meal with their usual portion size. An independent researcher weighed each ingredient and calculated the nutrients of the test meals. The participants took photographs of the test meals using a digital camera. Two independent, trained analysts measured the longitudinal and transverse diameters of the food area on the photographs of the test meals, compared the portion size with the reference photographs, and calculated the nutrients based on a database that contained reference photographs. RESULTS: Rank correlation coefficients between estimates from the food-photographic record of each test meal and weighed results were high for portion size (r = 0.93), energy (r = 0.93), protein (r = 0.90), fat (r = 0.92), and carbohydrate (r = 0.94), and those for the 44 nutrients ranged from 0.78 to 0.94. We found high reproducibility between the two analysts for all the nutrients (r > 0.90). CONCLUSIONS: We found a high correlation and small difference between the food-photographic record method and weighed results of a large number of nutrients in many test meals.

Variations in the estimated intake of acrylamide from food in the Japanese population.

BACKGROUND: Due to concerns of carcinogenicity, it is necessary to assess long-term acrylamide exposure in individuals. Whether the available methods of estimating acrylamide intake can indicate long-term exposure remains unknown. We examined variations in the estimated dietary acrylamide intake of the Japanese population. METHODS: The study included 240 participants aged 40-74 years who were a part of the Japan Public Health Center-based Prospective Study for the Next Generation (JPHC-NEXT). Twelve-day dietary records (DRs) were collected over a one-year period, and food frequency questionnaires (FFQs) were collected twice during the year. Dietary acrylamide intake was estimated from an acrylamide content database. Within-individual variations and between-individual variations were calculated using the random effects model. A linear regression analysis was performed to identify foods with large between-individual variations. RESULTS: The ratios of within-individual variance to between-individual variation were 3.2 for men and 4.3 for women. Days of DRs required to estimate the usual individual intake within 20% of the true mean intake with 95% confidence were 60 days for men and 66 days for women. Coffee/cocoa, potato, and green tea contributed to between-individual variations, in that order, and seven foods contributed to 93% of the between-individual variation. CONCLUSIONS: Estimating the acrylamide intake using DRs requires an extended data collection period to estimate the intragroup ranking and habitual intake of individuals. Long-term exposure assessments should be based on methods with less potential for measurement errors, such as the use of biomarkers.

Fruit and vegetable intake and pancreatic cancer risk in a population-based cohort study in Japan.

Oxidative stress and chronic inflammation are potential pathogenic factors of pancreatic cancer. Although fruits and vegetables are abundant in antioxidants and anti-inflammatory constituents, the reported associations between fruit and vegetable intake and pancreatic cancer risk have been inconsistent. Here, we investigated the association between fruit and vegetable intake and pancreatic cancer risk as part of the Japan Public Health Center-based Prospective Study. The analysis included 90,185 participants who responded to a medical and lifestyle questionnaire during 1995-1998. Associations between fruit and vegetable intake and pancreatic cancer risk were evaluated with Cox proportional hazards models. Additional analyses were stratified by smoking status and body mass index. During follow-up (median duration, 16.9 years), 577 participants were diagnosed with pancreatic cancer. In multivariate-adjusted models, pancreatic cancer risk was inversely associated with total fruit intake (highest vs. lowest intake quartile; hazard ratio [HR]: 0.74, 95% confidence interval [CI]: 0.57-0.95, p-trend: 0.116) and positively associated with total vegetable intake (HR: 1.30, 95% CI: 1.01-1.66, p-trend: 0.151). For total fruit intake, the inverse association with pancreatic cancer risk was more apparent in never smokers (HR: 0.67, 95% CI: 0.47-0.97, p-trend: 0.034). For total vegetable intake, the positive association was statistically significant in ever smokers (HR: 1.49, 95% CI: 1.01-2.19, p-trend: 0.043) and statistically nonsignificant in never smokers. In summary, total fruit intake and total vegetable intake had inverse and positive associations, respectively, with pancreatic cancer risk. Vegetable intake may correlate with increased risk partly because of the influence of smoking on vegetable intake.

Association of estimated dietary acid load with albuminuria in Japanese adults: a cross-sectional study.

BACKGROUND: Acid-base imbalance might promote the progression of chronic kidney disease (CKD), but whether nutrient-derived dietary acid load increases the risk of albuminuria or even high normoalbuminuria is unclear. METHODS: A Japanese cohort comprising 3250 men and 3434 women aged 40-97 years with urine albumin-to-creatinine ratio (ACR) < 33.9 mg/mmol or estimated glomerular filtration rate ≥ 15 ml/min/1.73 m2 were assessed. We performed a cross-sectional evaluation of the association between net endogenous acid production (NEAP), estimated as dietary protein to potassium content ratio, and the presence of high normoalbuminuria (ACR: 1.13-3.38 mg/mmol) or microalbuminuria. RESULTS: Median NEAP was 43.4 (interquartile range (IQR): 34.2-53.4) mEq/day in men and 35.0 (IQR: 27.7-43.6) mEq/day in women. Median ACR was 1.11 (IQR: 0.57-2.49) mg/mmol in men and 1.47 (IQR: 0.82-2.83) mg/mmol in women. In multivariate analysis, the adjusted odds ratio of the highest versus lowest NEAP quartile for microalbuminuria was 1.47 (95% confidence interval (CI): 1.08-1.99) in men and 1.54 (95% CI: 1.11-2.14) in women. For high normoalbuminuria or microalbuminuria, the adjusted odds ratio was 1.28 (95% CI: 1.02-1.59) in men and 1.39 (95% CI: 1.11-1.74) in women. From nutrient composition analysis, subjects with the highest potassium intake, but not protein intake, had lower adjusted odds ratios for the presence of microalbuminuria than those in the lowest quartile for potassium intake. CONCLUSIONS: Higher NEAP was associated with albuminuria and its association might negatively relate to potassium intake in an adult Japanese population.